Use of shrimp farm effluents for irrigation of Panicum maximum cvs.Tanzania and Mombaça

Abstract The study aimed to evaluate soil chemical changes and yield of two cultivars of Panicum maximum Jacq. (Tanzania and Mombaça) in response to irrigation with effluent from inland shrimp farming and compare the results with those obtained with conventional irrigation using river water. The experiment was carried out in a shrimp farm, in Russas-CE, Brazil. It was used a randomized block design, in a factorial 2 (grass cultivars) x 2 (types of irrigation water). The following yield variables were evaluated in four grass cuttings: height, dry matter yield and dry matter content. Data were analyzed by ANOVA and Tukey test. The following soil chemical properties were analyzed before and after treatment application: pH, electrical conductivity of saturated extract (CE), exchangeable sodium percentage (ESP), organic matter, P, K+, Ca2+, Mg2+ and Na+. Data were analyzed using t tests for paired observations, at 5% significance level. Irrigation with effluent from shrimp farming did not increased or reduced significantly dry matter yield of two cultivars of Panicum maximum as compared to irrigation with Jaguaribe river water. After 14 months of cultivation, levels of Na+, CE and ESP increased significantly (p < 0.05) in the soil irrigated with effluent, as compared to the soil irrigated with river water.

摘要：本研究旨在评估内陆虾养殖废水灌溉对大黍（Panicum maximum Jacq.）两个栽培品种（坦桑尼亚型与蒙巴萨型）土壤化学性质与产量的影响，并将结果与采用河水进行常规灌溉的处理组进行对比。实验于巴西塞阿拉州（CE）鲁萨斯市的一处虾养殖场开展，采用随机区组析因设计，因子组合为2（牧草品种）×2（灌溉水类型）。在四次牧草刈割中测定产量相关指标：株高、干物质产量及干物质含量，数据通过方差分析（ANOVA）与Tukey检验进行统计分析。分别在处理前后测定土壤化学性质：pH值、饱和浸提液电导率（CE）、交换性钠百分比（ESP）、有机质、磷（P）、钾离子（K+）、钙离子（Ca²+）、镁离子（Mg²+）与钠离子（Na+），采用配对样本t检验进行统计分析，显著性水平设定为5%。结果表明：与使用雅瓜里贝河（Jaguaribe river）河水灌溉的对照组相比，虾养殖废水灌溉并未显著改变两个大黍栽培品种的干物质产量。经过14个月的栽培后，与河水灌溉组土壤相比，施用废水灌溉的土壤中Na+含量、饱和浸提液电导率及交换性钠百分比均显著升高（p < 0.05）。